$a + b = 5 \\ a \: = 5 - b \\ a - b = 4 \\ 5 - b - b = 4 \\ 5 - 2b = 4 \\ 5 - 4 = 2b \\ 1 = 2b \\ \frac{1}{2} = \frac{2b}{2} \\0.5 = b \\ b = 0.5 \\ a = 5 - b \\ = 5 - 0.5 \\ = 4.5 \\ {a \: }^{2} - {b}^{2} = ( {4.5}^{2}) - ( {0.5}^{2} ) \\ = 20.25 - 0.25 \\ = 20 \\ {a}^{2} - {b}^{2} = 20$

Step-by-step explanation:

HOPE THAT THIS IS HELPFUL.

HAVE A GREAT DAY.

5 0

2 years ago

Worth all my points plus brainliest!!! Due in 4 hrs 1-11

SVETLANKA909090 [29]

Answer:

1. 15

2. -8/9

3. 5

4. 7

5. a = 20

6. n = 100

7. 3.6 x 10^1

8. 3

9. 4

10. 8.37 x 10^5

11. 6.67 x 10^3

8 0

2 years ago

Mr Coope drives 472 miles in 8 hours. At this rate, how many miles would he drive in 6

KatRina [158]

8hrs = 480mins
6hrs = 360 mins
472/480 = 0.983...
0.983... x 360 = 354
D) 354

6 0

2 years ago